The primary objective of the proposed research is to develop new methodology for general organic synthesis based on the organometallic chemistry of manganese. Preliminary results demonstrate that both aromatic systems and, remarkably, saturated carbon-hydrogen bonds can be specifically activated by manganese in fundamentally new and unique ways. Based on these initial studies, this chemistry can clearly be developed in a broad and general way for practical utility in organic synthesis. Although many diverse applications can be anticipated, immediate and specific aims include use of manganese activation in practical and efficient ways for (1) simple reduction of aromatic compounds to 1,3 cyclic dienes with introduction of functionalization at both vinyl saturated carbon sites; (2) further functionalization, with stereo and regio selectivity, of these dienes through unique metal-activated C-H bond substitutions; (3) rearomatization of these functionalized cyclohexadienes as new methods for aromatic substitutions; (4) conversion of cyclohexadienes to cyclohexenes with yet additional functionalization and stereochemical control; (5) general synthesis of dienes by introduction of substituents (again with stereochemical control) via direct electrophilic replacement of C-H bonds in simple diene complexes; and (6) conversion of these dienes to Z olefins with additional functionality. The general reactions to be developed will complement existing synthetic methodology and will be generally applicable to the synthesis of a diverse class of naturally occurring and/or biological active systems. As detailed in section 3, potential utility can be envisioned in the synthesis of certain carcinogenic polymethylated polycyclic aromatic hydrocarbons and the metabolically derived polycyclic aromatic diol epoxides, various pheromones, terpenoids, and alkaloids and specific classes of cytochalasans.